Question

An open flask sitting in a lab refrigerator looks empty, but it is actually filled with a mixture of gases called air. If the flask volume is 1.00 L, and the air is at standard temperature and pressure, how many gaseous molecules does the flask contain?

Answer 1

At standard temperature and pressure, any gas occupies $22.4l$

$\therefore$ $1l$ will be occupied by

$\frac{1}{22.4}\times1=0.04464\>moles$

But the number of particles in one mole of any substance is:

$6.023\times10^{23}$

Therefore, $0.04464 \,moles$ will have

$\frac{0.04464}{1}\times(6.023\times10^{23}$ $)$

$= 2.689\times10^{22}$ Molecules